A comparison of intrauterine hemopoietic cell transplantation and lentiviral gene transfer for the correction of severe β-thalassemia in a HbbTh3/+ murine model

Major hemoglobinopathies place tremendous strain on global resources. Intrauterine hemopoietic cell transplantation (IUHCT) and gene transfer (IUGT) can potentially reduce perinatal morbidities with greater efficacy than postnatal therapy alone. We performed both procedures in the thalassemic HbbTh3/+ mouse. Intraperitoneal delivery of co-isogenic cells at embryonic days13-14 produced dose-dependent chimerism. High-dose adult bone marrow (BM) cells maintained 0.2-3.1% chimerism over ~24 weeks and treated heterozygotes (HET) demonstrated higher chimerism than wild-type (WT) pups (1.6% vs. 0.7%). Fetalliver (FL) cells produced higher chimerism than BM when transplanted at thesame doses, maintaining 1.8-2.4% chimerism over ~32 weeks. We boosted transplanted mice postnatally with BM cells after busulfan conditioning. Engraftment was maintained at >1% only in chimeras. IUHCT-treated nonchimeras and non-IUHCT mice showed microchimerism or no chimerism. Improved engraftment was observed with a higher initial chimerism, in HET mice and with the addition of fludarabine. Chimeric HET mice expressed 2.2-15.1% engraftment with eventual decline at 24 weeks (vs. <1% in nonchimeras) and demonstrated improved hematological indices and smaller spleens compared with untreated HETmice. Intravenous delivery of GLOBE lentiviral-vector expressing human β-globin (HBB) resulted in a vector concentration of 0.001-0.6 copies/cell. Most hematological indices were higher in treated than untreated HET mice, including hemoglobin and mean corpuscular volume, but were still lower than in WT. Therefore, direct IUGT and IUHCT strategies can be used to achieve hematological improvement but require further dose optimization. IUHCT will be useful combined with postnatal transplantation to further enhance engraftment.

Rapid initiation of fetal therapy services with a system of learner-centred training under proctorship: the National University Hospital (Singapore) experience

INTRODUCTION

Management of complicated monochorionic twins and certain intrauterine structural anomalies is a pressing challenge in communities that still lack advanced fetal therapy. We describe our efforts to rapidly initiate selective feticide using radiofrequency ablation (RFA) and selective fetoscopic laser photocoagulation (SFLP) for twin-to-twin transfusion syndrome (TTTS), and present the latter as a potential model for aspiring fetal therapy units.

METHODS

Five pregnancies with fetal complications were identified for RFA. Three pregnancies with Stage II TTTS were selected for SFLP. While RFA techniques utilising ultrasonography skills were quickly mastered, SFLP required stepwise technical learning with an overseas-based proctor, who provided real-time hands-off supervision.

RESULTS

All co-twins were live-born following selective feticide; one singleton pregnancy was lost. Fetoscopy techniques were learned in a stepwise manner and procedures were performed by a novice team of surgeons under proctorship. Dichorionisation was completed in only one patient. Five of six twins were live-born near term. One pregnancy developed twin anaemia-polycythaemia sequence, while another was complicated by co-twin demise.

DISCUSSION

Proctor-supervised directed learning facilitated the rapid provision of basic fetal therapy services by our unit. While traditional apprenticeship is important for building individual expertise, this system is complementary and may benefit other small units committed to providing these services.

Augmented anti-tumor activity of NK-92 cells expressing chimeric receptors of TGF-βR II and NKG2D

The capacity of natural killer (NK) cells to kill tumor cells without specific antigen recognition provides an advantage over T cells and makes them potential effectors for tumor immunotherapy. However, the efficacy of NK cell adoptive therapy can be limited by the immunosuppressive tumor microenvironment. Transforming growth factor-β (TGF-β) is a potent immunosuppressive cytokine that can suppress NK cell function. To convert the suppressive signal induced by TGF-β to an activating signal, we genetically modified NK-92 cells to express a chimeric receptor with TGF-β type II receptor extracellular and transmembrane domains and the intracellular domain of NK cell-activating receptor NKG2D (TN chimeric receptor). NK-92 cells expressing TN receptors were resistant to TGF-β-induced suppressive signaling and did not down-regulate NKG2D. These modified NK-92 cells had higher killing capacity and interferon γ (IFN-γ) production against tumor cells compared with the control cells and their cytotoxicity could be further enhanced by TGF-β. More interestingly, the NK-92 cells expressing TN receptors were better chemo-attracted to the tumor cells expressing TGF-β. The presence of these modified NK-92 cells significantly inhibited the differentiation of human naïve CD4+ T cells to regulatory T cells. NK-92-TN cells could also inhibit tumor growth in vivo in a hepatocellular carcinoma xenograft tumor model. Therefore, TN chimeric receptors can be a novel strategy to augment anti-tumor efficacy in NK cell adoptive therapy.

Membrane IL1α Inhibits the Development of Hepatocellular Carcinoma via Promoting T- and NK-cell Activation

Hepatocellular carcinoma is a worldwide health problem with limited treatment options and poor prognosis. Inflammation associated with liver injury and hepatocyte regeneration can lead to fibrosis, cirrhosis, and eventually, hepatocellular carcinoma. IL1α is one of the most important inflammatory cytokines involved in inflammation and tumor development. IL1α presents as multiple forms in vivo, including precursor, propiece, membrane, and secreted forms, and their functions have been thought to be different. The role of membrane IL1α in hepatocellular carcinoma tumorigenesis is still not clear. Here, we examined the functions of membrane IL1α in murine hepatocellular carcinoma models. We found that membrane IL1α potently inhibited hepatocellular carcinoma tumor growth. Further studies showed that membrane IL1α promoted T- and natural killer (NK)-cell activation in vivo IFNγ production by CD8(+) T and NK cells was also increased as a result of membrane IL1α expression. Moreover, the cytotoxicity of the CTL and NK cells was also enhanced by membrane IL1α expression. Furthermore, in vitro studies demonstrated that membrane IL1α could directly activate T cells and NK cells in a cell contact-dependent manner. Conversely, depletion of both CD8(+) T and NK cells suppressed the antitumor activity of membrane IL1α. Our studies demonstrated that membrane IL1α could promote antitumor immune responses through activation of T and NK cells. Thus, our findings provide new insights of IL1α functions during hepatocellular carcinoma development. Cancer Res; 76(11); 3179-88. ©2016 AACR.